Fuel injection device for combustion chambers of internal-combustion engines



Nov. 22, 1949 w. FIRING FUEL INJECTION DEVICE FOR COMBUSTION CHAMBERS OF INTERNAL-COMBUSTION ENGINES Filed April 8, 1946 QJA Patented Nov. 22,139

CHAMBERS OF ENGINES Wilhelm Firing, Furulnnd, near Oslo,

A/S Thunea Mek. V

assignor to INTERNAL-COMBUSTION Norway, lcrhtell,

I Skoyen, near Oslo, Norway Application April 8,1948, Serial No. 5 0,534 In Norway October 5, 1842 section 1, Public Law s90, August a, 1946 Patent expires October-5, 1962 2 Claims. (c 123-33) It was formerly known in internal combustion motors to introduce liquid fuel into a small fuel chamber which communicates with a. separate combustion space and also with the top space of the cylinder, the small fuel chamber being cooled in order to prevent ignition; and from the said chamber the fuel while still not ignited was forced, towards the end of the compression stroke, into the combustion space of the engine carried by a current of air which passed through the small fuel chamber from a space located thereabove during a low pressure period in the combustion space, the connection between said small chamber and the space thereabove being throttled during the last piston motion towards the top position.

This invention aims at being able to control the moment of expelling the oil from the small fuel chamber and thereby also the ignition moment, and further to cause the air current which carries oil to set in with a great force The fuel, the oil, passes through a needle valve I and a non-retum valve 2 into the fuel chamber 3, when the pressure therein is less than the injection pressure of the oil, thus usually, during the charging and exhaust stroke or part of same, or during the scavenging period, in two-stroke cycle motors. The fuel chamber is formed in a throttling projection arranged in the motor head l and has the form of a pin 6 and is in permanent connection with the interior ofthe cylinder through channels 4- and 5 at two diflerent from the beginning and not to be builtup gradually, whereby the atomization would not be satisfactory, and finally to provide a special formation of the combustion space which is necessary to create the air current through the fuel chamber.

The invention is distinguished substantially by the throttling member enclosing or being connected with the fuel chamber and projects so from the cylinder that it throttles the last piston motion towards the top position.

A channel from the fuel chamber opens through the throttling projection into an aperture at such a location that the fuel during the throttling passes from the fuel chamber into the combustion space only when the pressure difierence between cylinder topspace and the combustion space has obtained a certain value.

The fuel chamber of the throttling projection may have a permanent connection with the cylinder at two heights one connection opening innermost into the top space and the other one somewhat out into the cylinder.

Further, outlet apertures from the throttling levels, but as long as the pressure at the point outside these channels is equal, no air current passes through the fuel chamber. and consequently the oil does not flow. As the fuel chamber, by water cooling, is maintained at a relatively low temperature, the oil will not ignite within the chamber which, besides, has an extremely small air content.

. Only toward the end of the compression period does piston reach a position where the throttling pin 6 extends into the combustion space I which formed in the piston.

The throttling which then takes place between :5 the space 8 above and the space I in the piston projection may be directed nearly perpendicular to the air current which passes out of the projection direct from the cylinder space into the combustion space of the piston, for the purpose of intensifying the atomization.

Further the invention relates to features which will be mentioned in connection with the drawing which shows an embodiment in a longitudinal section through the upper part of a cylinder of the motor and its head piece.

results ina pressure difference which creates a stream from 8 into I in the constricted opening 9 between throttling pin and piston and also through channel I via fuel chamber 3 out through channel 5. This air current through the fuel chamber carries the oil with it out through apertures 5. The air-mixed oil meets the air from section 9, whose velocity assists in creating a turbulence in space I and thereby a good mixing.

The moment of expelling the oil from the oil; chamber depends upon the condition, how long before the top position the governing edge ll of the piston passes bythe aperture 5 which is then exposed to a sudden fall in pressure.

Up to the moment the governing edge II in travelling upwards in passing by the end of pin 6, the pressure in space I and the rest of the cylinder volume 8 will be practically identical. In accordance with the travel of the piston further upwards, the pressure difference between I and 8 increases gradually and obtains its maximum, when the pin 8 has projected into space 1 to a considerable extent. Besides, the condition will be dependent upon the relative dimensions of the spaces 1 and 8 and of the pin 8. By arranging the aperture 5 at a distance up from the pin end, the stream through the oil chamber which sets in only when the edge ll passes by the aperture 5, will take place immediately during a great pressure difference, that.

amass? 3 is with a high velocity and with turbulence caused thereby.

The throttling projection need not be in the form of a pin. It may also be an offset which may be arranged in the middle of or on the side of the piston or of the head piece.

Instead of the needle valve I a mechanically governed valve may be provided, so that the oil supply, independently of the other conditions, is open only during a certain portion of the crank angle, so that the valve determines the moment and/or the section of the oil supply into the fuel chamber. The fuel quantity may then be regulated by varying the lift and/or the opening time of the mechanically controlled valve.

I claim:

1. In an injection type internal combustion engine, walls forming a cylinder including a cylinder head, a piston reciprocable in said cylinder so as to approach close to the cylinder head during the compression stroke, said piston having acombustion chamber of substantial size formed therein, said combustion chamber having an opening through the top surface of the piston, an injection nozzle extending into the interior of the cylinder at a position to enable it to enter the combustion chamber opening in the piston when the piston approaches the cylinder head, and being of sufficient size to reduce the flow area of the combustion chamber opening when protruding therein, said injection nozzle having a liquid fuel chamber formed therein and a non-return valve controlling the inlet to said fuel chamber, said nozzle having an opening extending to the fuel chamber from a point on a side of the nozzle remote from its inner end and also having an opening formed therein extending transversely to the axis of said combustion chamber opening from said fuel chamber to a point in a side wall of the nozzle closer to the inner end of said nozzle whereby, when the inner end of the nozzle enters the opening of the combustion chamber and constricts said opening a substantial pressure differential is created between the combustion chamber and end of the cylinder and air passes into the fuel nozzle through the first mentioned openings therein and out of said second mentioned openings carrying fuel with it, and also air passes into the combustion chamber through the constricted opening in a direction substantially at right angles to the air and fuel passing out of the second mentioned opening of the nozzle whereby turbulence in the air-fuel mixture is increased.

2. In an injection type internal combustion engine, walls forming a cylinder including a cylinder head, a piston reciprocable in said cylinder so as to approach close to the cylinder head during the compression stroke, said iston having a combustion chamber of substantial size formed therein, said combustion chamber having an opening through the top surface of the piston, an injection nozzle extending into the interior of the cylinder at a position to enable it to enter the combustion chamber opening in the piston when the piston approaches the cylinder head, and being of sufiicient size to reduce the flow of the combustion chamber opening when protruding therein, said injection nozzle having a liquid fuel chamber formed therein and a non-return valve controlling the inlet to said fuel chamber, passages for circulation of cooling fluid formed in said nozzle to prevent ignition of the fuel in the fuel chamber in the nozzle, said nozzle having an opening extending to the fuel chamber from a point on a side of the nozzle remote from its inner end and also having an opening formed therein extending transversely to the axis of said combus tion chamber opening from said fuel chamber to a point in a side wall of the nozzle closer to the inner end of said nozzle, whereby when the inner end of the nozzle enters the opening of the combustion chamber and constricts said opening a substantial pressure differential is created between the combustion chamber and end of the cylinder and air passes into the fuel nozzle through the first mentioned openings therein and out of said second mentioned openings carrying fuel with it, and also air passes into the combustion chamber through the constricted opening in a direction substantially at right angles to the air and fuel passing out of the second mentioned opening of the nozzle whereby turbulence in the air-fuel mixture is increased.

- WILHELM FIRING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 669,737 Thomson Mar. 12, 1901 887,393 Haselwander May 12, 1908 I 1,437,396 Brush Dec. 5, 1922 M 2,972,574 Witkowski Mar. 2, 1937 FOREIGN PA'IENTB Number Country Date 636,154 France Apr. 3, 1928 690,583 France Sept. 23, 1930 

